Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis and emphysema. COPD is generally characterized by airflow obstruction, which in particular limits the patient's air flow during expiration. Patients with chronic bronchitis have chronic cough with sputum production leading to obstructed expiration. In patients with emphysema, destruction of lung parenchyma can lead to loss of elastic recoil, reduced tethering of the airways, obstruction to expiration, and cough.
Lung function as well as quality of life in patients suffering with a COPD can be improved by reducing a patient's effective lung volume. One way to reduce effective lung volume is by surgically removing diseased portions of the lungs, both to promote expansion of the non-diseased regions, realign a patient's diagraph and to redirect inhaled air from diseased portions of lungs into healthier, better functioning lung regions. Surgery often results in effective volume reduction of about 15-30%, which may not be sufficient to cause an appreciable improvement in lung function. Also, conventional lung reduction surgery is traumatic, even when thorascopic procedures are employed.
Recently, bronchoscopic approaches for reducing effective lung volume have been proposed. See for example, U.S. Pat. Nos. 6,592,594, 6,679,264, 6,398,775 and 6,610,043; and U.S. Patent Publications 2003/0181922, 2004/0055606, and 2004/0047855. One challenge to achieving effective lung reduction, particularly in emphysematous lungs, is collateral ventilation or collateral pathways.
Accordingly, there is a need for devices, methods and systems for reducing effective lung volume without surgery, and also for reducing lung volume in the presence of collateral pathways. The present invention is directed to meeting these, as well as other, needs.